A pneumatic tire assembled onto a rim commonly causes a cavity resonance phenomenon due to an internal shape of the tire while a vehicle runs, and thereby noise, so-called “road noise”, is caused in an interior of the vehicle during the running. The cavity resonance has a frequency within a range of 180 to 300 Hz and forms a sharp peak when it is transmitted to an axle, differently from other bands, and thereby contributes to the noise in the interior of the vehicle.
To this problem, JP-A-H01-115701 discloses a technique for suppressing the cavity resonance phenomenon by using a wheel rim having the specified structure. However, the wheel rim disclosed in JP-A-H01-115701 has a sophisticated structure comprising a cavity portion communicating with a tire internal cavity, and therefore it is difficult to produce the wheel rim and cost of the tire-rim assembly must become high.
On the other hand, JP-B-3622957 discloses a tire-rim assembly wherein a strip-shaped sheet not having a ring shape is fixed in a tire internal cavity defined by the tire and the rim and the strip-shaped sheet has a specific gravity within a specified range, as a tire-rim assembly capable of reducing the road noise during the running without deteriorating rim assemblability.